Hello,
Unless there is thinning or balding, I would not use minoxidil/regrowth to get a growth spurt. I don't think it will cause the kind of growth spurt you want anyway, but more importantly hair that starts growing in from using minoxidil becomes "minoxidil-dependent" and will shed once the minoxidil treatment is stopped.
There are lots of posts/threads about using MN and/or MTG to help with growth spurts. Those are probably better choices than minoxidil unless you have thinning or balding.
I personallly have had success from vitamins (biotin and hair vitamins) and increasing protein intake.
HHG